Research | Concepts | Seismic Reflection Exploration

Copyright Kerry Key 2003

The seismic reflection method is the primary tool for offshore exploration.
A survey ship releases high pressure explosions ("shots") from an air gun array.
The pressure wave expands out form the shot location and forms reflections
waves from the boundaries and layers of geologic structure. The reflected waves
are then measured on hydrophones (underwater microphones) towed behind the
ship on the sea surface. By knowing the time of the air gun shot and the time
the waves reach the hydrophones, the layering and geologic boundaries of
the subsurface can be reconstructed.

An example of a depth migrated seismic reflection profile from Gemini
Prospect, Gulf of Mexico is shown below. The black and white area correspond
to different layers within the seafloor. The brightest reflections are from
a salt intrusion.